1. Field of the Disclosure
The present invention relates to a device and method for mixing and applying biomaterials. More particularly, it pertains to a device comprising a plunger, a mixing surface, and a retractor locking assembly assembled such that the mixing surface can be locked into an extended or a retracted position, and a method wherein the mixing surface is locked in the extended position to mix the biomaterials and locked in the retracted position to apply the biomaterials.
2. Description of the Background of the Disclosure
Bone fillers and cements are widely used in the medical field. Such cements are made by mixing a liquid and powdered component to form a paste which then sets to form a hard cement or filler. These pastes may be placed in situ prior to setting in situations where a bone has been broken, destroyed, degraded, or become too brittle, or as a suture anchor used to attach soft tissue to bone. Rapid setting bone cement compositions are advantageous due to the shortened time required for surgery and recovery after surgery.
One such bone cement is disclosed in U.S. Publication 2010/0121459 to Garigapati comprising tetracalcium phosphate, phosphoserine, and an aqueous medium. Another bone cement disclosed in U.S. Publication 2011/0277931 to Garigapati includes a reactive mixture of a small amino acid phosphate species, a multivalent metal compound, and a polymeric material in an aqueous environment. The multivalent metal compound may be a calcium phosphate, or, more specifically, a tetracalcium phosphate. The small amino acid phosphate species may be phosphoserine or a compound with a similar structure. The bone cement disclosed in U.S. Ser. No. 61/558,214 comprises a non-covalently bonded macromolecular network comprising of a reactive mixture of a small amino acid phosphate species and a bioactive glass material in an aqueous environment. Similar bone cements are further disclosed in U.S. Ser. No. 61/486,064 and U.S. Publication No. 2009/0110743.
In these compositions, the powder component, which includes the calcium phosphate, is supplied in a bottle. The liquid, which includes the phosphoserine or phosphoserine-like substance and optionally other additives such as a polymer or bioactive glass material, is provided in a glass container. The components are usually mixed in a mixing container and transferred to a vessel such as a syringe to be dispensed.
An assembly for mixing a powdered copolymer and a liquid monomer to form a bone cement and delivering the bone cement is disclosed in U.S. Pat. No. 6,547,432 to Coffeen et al. The device comprises a cartridge having a distal end and a proximal end, defining a mixing chamber and having a mixing blade therein. A transfer mechanism supporting a piston and a plunger is connected to the distal end to dispense the bone cement from the proximal end. The device further comprises a removable handle for insertion through the proximal end and attachment to the mixing blade by a quick-release connector. After removal of the handle, the mixing blade remains in the mixing chamber as the bone cement is dispensed from the proximal end.
Another assembly for mixing and delivery is described in U.S. Pat. No. 7,658,537 to Coffeen et al. The device includes a mixer connected to a delivery device by a transfer conduit. Separate components are mixed in the mixer and then automatically transferred through the transfer conduit to the delivery device for delivery of the mixture to the target site.
A further assembly for storing, mixing, and dispensing components disclosed in U.S. Pat. No. 7,736,049 to Keller consists of a first container for a powdery material, a second container for a liquid material, a piston assembly for transferring the liquid component to the first container, a mixing arrangement for mixing the powdery and the liquid components in the first container, and a piston assembly for dispensing the mixed materials. The assembly further comprises a transfer area between the outlet of the second container and the inlet of the first container.
Problems arise when preparing to dispense a bone cement composition onto a host area using a syringe. Additional time is needed to transfer the cement composition from a mixing container into the syringe, or, for the assemblies described above, to attach and detach various parts. Further, such transfer requires the use of both hands. It is therefore necessary to provide a device for mixing and applying biomaterials designed to allow the substance to be mixed and applied from the same vessel, where the device can be locked in either an extended position in order to mix the substance or in a retracted position in order to apply the substance. Further, it is ideal to provide a device that can be rotated relative to the vessel upon movement of the vessel in a circular motion.